This application relates to a spring that is provided with a damper to reduce bouncing.
Gas turbine engines are known and, typically, include a fan delivering air into a compressor. The air is compressed in the compressor and delivered into a combustion section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors driving them to rotate.
The turbine rotors are provided with bearings. One challenge with gas turbine engines is called “windmilling.” Windmilling may occur when the engine is shut down, but air is driven across the fan rotor. The fan rotor may rotate in a reverse direction than is typical for the engine and, in turn, drive a fan drive turbine shaft. This can be detrimental to the bearings.
Thus, it has been proposed to provide a ratchet, counterweight and pawl system which prevents reverse rotation of the shaft. Typically, a pawl is biased outwardly into engagement with a ratchet and such that the shaft will not rotate in the reverse direction. The pawls will not engage when the shaft is driven in the proper direction, but will slide along the ratchets.
At start-up, the pawl is provided with a counterweight that will move the pawl out of engagement once the engine reaches a particular speed. Until the counterweight moves the pawl out of engagement, there is movement of the pawl along the ratchets as the engine is driven in the desired direction.
There can be a bouncing mode that is undesirable during this movement.